Parachute harness and release mechanism therefor

ABSTRACT

The invention concerns an ejection seat escape installation for providing escape from a vehicle where it is not possible to provide an escape opening directly above an ejection seat, the installation being particularly applicable to rotor aircraft such as a helicopter, the installation comprising at least one ejection seat carried by a frame, means angularly to incline the seat and the frame and a rocket motor to cause the ejection seat to deviate from the trajectory which it would normally take under the influence of the standard ejection gun of the seat.

United States Patent [451 Oct. 31, 1972 Martin [54] PARACHUTE HARNESSAND RELEASE MECHANISM THEREFOR [72] Inventor: James Martin, SouthlandsManor,

Southlands Road, Denham, near Uxbridge, Middlesex, England -221 Filed:March 22,1971

[21] Appl.No.: 126,614

[30] Foreign Application Prlorlty Data April 16, 1970, Great Britain..l8,238/70 [52] US. Cl. ..244/122 AD [51] Int. Cl. ..B64d 25/10 [58]Field of Search.....244/l22 AD, 122 A, 122 AB, 244/122 AC, 141

[56] References Cited UNITED STATES PATENTS 2,671,622 3/1954 Saulnier..244/ 141 X 3,222,015 12/ 1965 Larsen et a1. ..244/122 A X 3,361,3971/1968 Valentine ..244/122 AD 3,606,221 9/ 1971 Morris et al ..244/122AD Primary Examiner-Milton Buchler Assistant Examiner-Carl A. RutledgeAttorney-Kurt Kelman 57 ABSTRACT Theinvention concerns an ejection seatescape installation for providing escape from a vehicle where it is notpossible to provide an escape opening directly above an ejection seat,the installation being particularly applicable to rotor aircraft such asa helicopter, the installation comprising at least one ejection seatcarried by a frame, means angularly to incline the seat and the frameand a rocket motor to cause the ejection seat to deviate from thetrajectory which it would normally take under the influence of thestandard ejection gun of the seat.

6 Claims, 3 Drawing Figures PATENTED UB1 3 1 I972 SHEEI 1 BF 2 lnvenlorJames MnRr/N By Mul KM AGE v1- Thus one object of this invention is toprovide a system which will permit safe escape from a vehicle where noopening can be provided above the ejection seat. One typical conditionfrom which escapeis difficult is where more than one ejection seat isplaced adjacent, yet not immediately beneath, a single escape hatch oropening of a size sufficient for only one seat to pass therethrough atonetime.

Thus broadly in accordance with this invention there is provided anejection seat installation comprising an ejection seat having anejection gun and a rocket motor, said ejection seat being mounted uponan angularly movable frame, means being provided to move said frameangularly from a normal seating position to a sidewardly inclinedposition to align said seat with an escape opening in a vehicle in whichthe installation is to be fitted.

The invention especially concerns ejection seat installations forenabling the safe escape of airmen from a helicopter.

It is well known to provide ejection seats for facilitating the escapeof airmen from aircraft but, it will be appreciated that the escape fromrotor aircraft, for example, helicopters is made more difficult by thepresence of the helicopter rotor which rotates above the helicoptercockpit. Thus escape in an ejection seat upwardly from the cockpit isnot possible because of the clearly severe risk of collision of theejection seat and airmen with the rotor. Equally escape in an ejectionseat downwardly from the cockpit is unsatisfactory insofar that downwardejections can only be carried out with any reasonable degree of safetyat very high altitudes and apart from the fact that helicopters rarelyoperate at high altitudes this downward ejection system could notprovide a zero or near zero altitude safe ejection capability.

A further object of this invention is therefore to pro? vide a new orimproved ejection seat escape installation to enable safe escape ofairmen from helicopters.

Thus more specifically, and according to another aspect of thisinvention, there is provided an ejection seat installation comprising anejection seat having an ejection gun and a rocket motor, said ejectionseat being mounted upon an angularly movable frame, means being providedto move said frame and seat angularly from a normal seating position toa sidewardly inclined position and said rocket motor being arranged toproduce a thrust inclined sidewardly to the direction of thrust of theejection gun, the arrangement being such that on initiation of theejection seat firing sequence such seat is first moved angularly saidsideways direction whereupon the ejection gun is fired andsimultaneously or shortly thereafter said rocket motor is ignited, thethrust of said rocket motor being sidewardly inclined to the initialdirection of thrust of the ejection gun so that the seat/airmancombination is urged to follow an upwardly directed curvilineartrajectory.

Expediently said rocket motor may have its outlet nozzle or nozzleslocated beneath the seat pan of the ejection seat, such rocket motoroutlet nozzles or nozzles being inclined with respect to the ejectiongun thrust line.

Conveniently a plurality of rocket motor propellantcontaining canistersare provided to create a rocket motor pack, and in addition to theprovision of said inclined nozzle(s) or alternatively thereto, the packis provided with at least two spaced apart outlet nozzles, one nozzlebeing of a greater diameter than the other so that an asymmetricalthrust is provided which applies a sideways tilting moment to the seat.

Alternatively, however, the rocket motor may merely be provided with oneor more outlet nozzles which are inclined to the thrust line of theejection gun and such rocket motor may be positioned at, or near, thehead or upper part of the seat. It will be appreciated that more thanone rocket motor or a pack of rocket motors may be applied to such headof the seat.

Still further it will be understood that a rocket motor(s) may beprovided beneath the seat pan as well as a rocket motor(s) at the headof the ejection seat.

For example the thrust of the rocket motor positioned beneath the seatpan may be chosen to be symmetrical or asymmetrical but to supplementthe thrust of the ejection gun and adjustment of the seat trajecto ry tolift the same may be effected or 'aided by one or more rocketsprovided,for example, at the top or head of the seat and having sidewardlydirected thrust lines.

In order that the invention may be more readily understood oneembodiment of ejection seat escape system for enabling escape from ahelicopter will now be described, by way of example and with referenceto the accompanying drawings in which:

FIG 1 is a diagrammatic front elevation of a two seater helicopterprovided with ejection seats in accordance with this invention;

FIG. 2 is a diagrammatic side elevation of one such ejection seat; and

FIG. 3 is an underneath plan view of a rocket pack of the seat.

Whilst at least two airmen normally comprise the crew of a helicopterand they are seated side-by-side in the cockpit of the helicopter asshown in FIG. 1, for the sake of convenience and clarity the escapeinstallation for one only of the crew members will be describedhereinafter although certain parts of both ejection seats in FIG. 1 willbe provided with reference numerals.

The system comprises an ejection seat 1 comprising a basic seat frame 2carrying thereon a seat pan 3. The frame is provided with an ejectiongun 4 extending upwardly along the back thereof (between a pair of beamsin a known manner) and a rocket motor pack 5 is located beneath the pan3 of the seat 1. Such a general form of ejection seat construction iswell known and is clearly described in, for example, the specificationsof my US. Pat. Nos. 3,186,662; 3,124,324; and application No. 708,201.

In the present construction however the ejection seat 1 including theseat frame 2 and gun 4 is pivotally connected to the helicopterstructure so as to be capable of being moved from a position in whichthe seat 1 is in its normal operational upright position (i.e. with theairman seated upright in the seat) to a sidewardly inclined motorposition as shown in FIG. 1 where the seat is disposed approximately 80from said operational positionafter movement in the direction of arrowA.

Movement of the seat as a whole to this inclined position may beeffectedin many ways but conveniently the seat is supported at its baseon a single pivot point 6 on 'the floor of the helicopter and the seatis moved about such pivot point 6 in response to the action ofextendible hydraulic or other pressure fluid operated rams onlydiagrammatically shown and designated 7.

In this embodiment the rocket motor pack comprises a plurality ofpropellant containing canisters 8 interconnected by a common spine 9which is provided at opposite ends with outlets 10, 11 encircled bythrust nozzles. The diameters of the outlets 10, 11 which are located atopposite ends of spine 9 are of different diameters, the outlet 11 beinglarger than the outlet so that an asymmetrical thrust will be providedby the rocket motor pack as a whole and one side of the seat will tendto tilt sideways under the effect of the rocket motor pack once it isignited.

To avoid serious displacement of the user of the seat during the 80tilting of the seat 1 during the escape procedure, side guards 13normally stowed in flatcontainers 14 situated on at least one side ofthe seat pan are deployed. Deployment may be effected either by releaseof a spring mechanism or, as indicated in FIG. 2 by pressure fluidintroduced into the container 14 from a canister 15.

In an emergency, an airman desiring to leave his helicopter would merelyactuate the ejection seat firing mechanism which would'first causeopening or jettisoning of the side door of his cockpit, wouldsimultaneously cause. the deployment of side guards 13 in the directionof arrows B to prevent sideways displacement of the airman duringejection, would then cause unlocking of the upper portion of theejection seat from the helicopter structure whereupon the rams 7referred toabove would be extended so that the seat 1, and the airmanseated therein, will be moved angularly in the direction of arrow A sothat the upper end of the seat 1 protrudes through the opening in theside of the helicopter cockpit. When this stage is reached in theejection sequence the seat-1 is locked in position either by locking ofthe rams 7 or 6 by a separate lock mechanism and the ejection gun 4 isfired so that the seat would be thrust in a direction sideways of thehelicopter in a slightly upwardly inclined direction (at least when thehelicopter is in a horizontal position). The thrust direction isselected so that when compensated by gravity the trajectory followed bythe seat/airman combination would not coincide with the path of movementof the helicopter rotor 16.

It will be understood that the upward inclination of the trajectorycannot be very substantial if the rotor 16 I diagrammatically in FIG. 1.

In certain instances it may be desirable to provide the rocket motor 5with a symmetrical thrust or to dispense with a rocket motor 5 beneaththe seat pan 3 altogether and in such an instance a rocket motor wouldbe pro vided towards the head of the seat, the thrust line of thisrocket being chosen so that it is substantially transverse to thegeneral direction of the thrust line of ejection seat gun.

It will be understood that time delay mechanisms could conveniently beincorporated into the seat so that the rocket motor would not becomeeffective until the ejection seat lies outside the circle defined by therotor.

It should be understood that in dependence upon the particulartrajectory required for any particular helicopter escape the extent ofangular movement of the seat prior to the ejection gun being fired maybe varied as can the extent of asymmetry of the thrust of any rocketmotor positioned beneath the seat pan of the ejection seat. Likewise thethrust, thrust direction and initiation time of any additional oralternatively provided transversely directed rockets at the head of theseat may be adjusted to suit particular trajectory requirements.

Where the helicopter is provided with a two ejection seat installationas shown in FIG. 1 then all the ejection steps may be carried outsimultaneously for both seats, the seats leaving the helicopter fromopposite sides of the cockpit.

Very conveniently the seats in such an installation would be operativelyintercoupled so that operation by either airman of the ejection sequenceof his seat is automatically transmitted to the seat of the other airmanso that simultaneous ejection can take place with a minimum of delay.

It will be understood that the other known features of my ejection seatswould be utilized such as automatic tensioning of the airman s seatharness.

Once ejection has taken place automatic deployment of the parachuteswould take place after the ejection seats has cleared the path of therotor and has reached a sufficiently high position along its trajectory.

Whilst the parachute could be deployed in any known manner by means of,for example, a drogue gun etc., conveniently a static line would becoupled to the helicopter structure which static line would also becoupled to a main parachute deploying mechanism carried by the seat sothat the parachute may be extracted and deployed very rapidly atprecisely the correct time. In the case of escape from helicopters (asopposed to escape from high speed aircraft) it is possible to deploy theparachutes by means of a static line after the ejection seat has movedto a predetermined distance from the helicopter as helicopters tend tohave an inherent stability even when their rotors are stopped andfurthermore travel at low speeds where there is unlikely to be anydanger of the main parachute opening explosively.

Iclaim: I

1. An ejection seat installationcomprising an ejection seat having:

an ejection gun; a rocket motor;

an angularly movable frame upon which said ejection seat is mounted;

means being provided to move said frame angularly from a normal seatingposition to a sidewardly inclined position to align said seat with anescape opening in a vehicle in which the installation is to be fitted.

2. An ejection seat installation comprising an ejection seat having:

an ejection gun;

a rocket motor;

an angularly movable frame upon which said ejection seat is mounted;

means being provided to move said frame and seat angularly from a normalseating position to a sidewardly inclined position;

said rocket motor being arranged to produce a thrust inclined sidewardlyto the direction of thrust of the ejection gun;

the arrangement being such that on initiation of the ejection seatfiring sequence such seat is first moved angularly in said sidewaysdirection whereupon the ejection gun is fired and simultaneously orshortly thereafter said rocket motor is ignited, the thrust of saidrocket motor being sidewardly inclined to the initial direction ofthrust of the ejection gun so that the seat/airman combination is urgedto follow an upwardly directed curvilinear trajectory.

3. An installation according to claim 2 wherein said rocket motorcomprises:

a plurality of rocket motor propellant containing canisters;

a spine intercoupling such canisters;

structure of the spine defining two spaced apart outlet nozzles, onenozzle being of a greater diameter than the other so that anasymmetrical thrust is provided which applies said sideways tiltingmoment to the seat.

4. An installation according to claim 2, wherein a rocket motor isprovided;

structure of said motor defining at least one outlet arranged to providea thrust line which is sidewardly inclined to the thrust line directionof said ejection gun on the seat.

5. An installation according to claim 3, wherein said rocket motor alsosupplements the thrust of the ejection gun.

6. A rotor vehicle such as a helicopter provided with at least oneejection seat installation in accordance with claim 1.

1. An ejection seat installation comprising an ejection seat having: anejection gun; a rocket motor; an angularly movable frame upon which saidejection seat is mounted; means being provided to move said frameangularly from a normal seating position to a sidewardly inclinedposition to align said seat with an escape opening in a vehicle in whichthe installation is to be fitted.
 2. An ejection seat installationcomprising an ejection seat having: an ejection gun; a rocket motor; anangularly movable frame upon which said ejection seat is mounted; meansbeing provided to move said frame and seat angularly from a normalseating position to a sidewardly inclined position; said rocket motorbeing arranged to produce a thrust inclined sidewardly to the directionof thrust of the ejection gun; the arrangement being such that oninitiation of the ejection seat firing sequence such seat is first movedangularly in said sideways direction whereupon the ejection gun is firedand simultaneously or shortly thereafter said rocket motor is ignited,the thrust of said rocket motor being sidewardly inclined to the initialdirection of thrust of the ejection gun so that the seat/airmancombination is urged to follow an upwardly directed curvilineartrajectory.
 3. An installation according to claim 2 wherein said rocketmotor comprises: a plurality of rocket motor propellant containingcanisters; a spine intercoupling such canisters; structure of the spinedefining two spaced apart outlet nozzles, one nozzle being of a greaterdiameter than the other so that an asymmetrical thrust is provided whichapplies said sideways tilting moment to the seat.
 4. An installationaccording to claim 2, wherein a rocket motor is provided; structure ofsaid motor defining at least one outlet arranged to provide a thrustline which is sidewardly inclined to the thrust line direction of saidejection gun on the seat.
 5. An installation according to claim 3,wherein said rocket motor also supplements the thrust of the ejectiongun.
 6. A rotor vehicle such as a helicopter provided with at least oneejection seat installation in Accordance with claim 1.